NdFeB neodymium iron boron permanent magnet has two polarities, magnetic north pole N, magnetic south pole S. After cutting, it is still two poles N and S poles. A single magnetic pole cannot exist. At the same time, NdFeB neodymium iron boron permanent magnet has directivity. Hang up, you will find that its south pole points to the geographic south pole, and the north pole points to the geographic north pole. Its characteristics determine that NdFeB neodymium iron boron Permanent magnets can be widely used in fields such as motors, communications, medical treatment, electronic instruments, magnetic separators, aerospace and daily necessities.

Precision NdFeB Permanent Magnet

Electric machinery, communication, medical treatment, electronic instrumentation, magnetic separator, aerospace and daily necessities, etc. It has been widely used in generators, motors, compasses, etc., such as magnetic pumps. Neodymium iron boron permanent magnets can also be used to generate electricity, and most of the current power generation equipment uses coils to cut the magnetic field of the magnet to generate electricity.

In recent years, the technology of electromagnets made with superconducting coils has been rapidly developed. Due to the high current density of superconducting wires, the resistance is almost zero during superconducting state operation, making it easier to manufacture strong magnets above 5-10T. In particular, the electromagnets for conduction cooling of refrigerators do not need to use expensive liquid helium, which greatly expands the application fields of superconducting magnets.

The largest application area of NdFeB neodymium iron boron permanent magnet materials in China is audio, accounting for 27%. The applications in audio include speakers, headphones and so on. The magnetic circuit structure of the loudspeaker is divided into internal magnetic type and external magnetic type. When using rare earth permanent magnetic materials, it can be applied to both internal magnetic and external magnetic structures, and the size and weight are greatly reduced. At present, some domestic and foreign manufacturers of advanced audio equipment have introduced NdFeB neodymium iron boron speakers, which have greatly improved their electroacoustic performance. A large number of exported speaker magnets in my country are mainly used in high-performance stereo headphones. Magnetic permeability is a physical quantity that represents the magnetic permeability of a magnetic medium. The relative permeability of neodymium iron boron magnets at room temperature is generally 1.05, high coercivity such as UH, EH, and products with better production technology, can be as low as 1.02, 1.03.

Neodymium iron boron magnet

The higher the coercivity of the neodymium iron boron magnet, the lower the relative permeability. Sintered NdFeB permanent magnet materials are divided into low coercive force N, medium coercive force M, high coercive force H, super high coercive force SH, ultra-high coercive force UH, and extremely high coercive force according to the coercive force of magnetic polarization strength. Six types of high coercivity EH products, among which the relative permeability of extremely high coercivity EH can reach 1.02. Saturate and magnetize magnets of the same size of UH, EH, SH, and N grades. After measuring the magnetism of the meter, put them in boiling water and boil for more than 1 hour, take them out and cool to room temperature, and then measure the magnetism of the meter. . The most demagnetized is N, followed by SH and UH, and the least demagnetized is EH. NdFeB Magnets can be divided into two types: bonded NdFeB and sintered NdFeB. Bonding is actually injection molding, while sintering is vacuumed and heated at high temperature. Neodymium iron boron magnets are permanent magnets with the strongest magnetic force so far.

Permeability is usually represented by the symbol μ, which is the permeability of the medium, or absolute permeability. μ is equal to the ratio of the magnetic induction intensity B to the magnetic field intensity H in the magnetic medium, that is, μ=B/H=μ0×μr, where μ0 is the permeability of the vacuum, and μr is the relative permeability of the medium. According to the size of μr, the medium Divided into paramagnetic (μr>1), diamagnetic (μr<1) and ferromagnetic (μr>>1).